The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
FIG. 1 shows an example of a method 10 for performing atomic layer deposition (ALD) of SiO2 via reaction of silicon precursors with oxidizing co-reactants (ozone, oxidizing plasmas, etc.). Inert and/or reaction gases may be introduced into a process chamber. At 12, a precursor dose is introduced into the process chamber. Some of the precursor is adsorbed onto an exposed surface of the substrate and remaining precursor is removed from the process chamber at 14. For example, the substrate may include a semiconductor wafer. At 16, the adsorbed precursor is activated, typically using plasma. At 20, post activation removal of reactants is performed.
ALD processing may tend to have relatively long cycle times due to the amount of time required for the precursor to adsorb onto the exposed surface of the substrate. Contamination may occur due to the transients caused by cycling of the plasma on (during activation of the adsorbed precursor) and off (during dosing of the precursor).